1. Field of the Invention
The present invention relates to internal combustion engines and, more particularly, to a carburetor.
2. Brief Description of Prior Developments
U.S. Pat. No. 6,347,787 discloses a carburetor with two passages and two valves. The valves are connected by gears for different motions relative to each other. U.S. Pat. No. 6,216,650 discloses a stratified engine with a carburetor and an ON/OFF valve. U.S. Pat. No. 6,349,925 discloses a carburetor with an air valve shaft and a throttle valve shaft movably coupled to each other.
It has been observed that when a large size main jet is used in a double barrel carburetor, the hydrocarbon emission is very high. When a small size jet or the needle is adjusted for low emission at idle, the acceleration may become unsatisfactory. There is a desire to provide a carburetor for a stratified engine which can allow air to flow through an air channel at idle and at wide open throttle (WOT), but which can block flow through the air channel at a predetermined intermediate position or range.